in my honest thougts take all who care with you. Be careful and keep us posted you sound like you want to see him, for some odd reason..
he has come back to see the two of you for a reason.. He may be on vaction, I am not sure, sound werid... I am not sure about that either.
Makes one wonder why he would leave a good job and come back to see you and your sis unless somehting is up.. He could be sick and wants to make amends for things he had done in the past never know untill you go and see him..
As long as you knwo you are going to be safe and secuer in seeing him, do not let him in any home.. DO it in a public place till you know all is well ok..
Go with your gut sundance. ok.
Trust me on this one.. Sometimes people from our past do not always have good intetions no matter how good they tend to sound.